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Malik A, Singh KP, Mohan D, Patel DK. Distribution of polycyclic aromatic hydrocarbons in Gomti river system, India. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2004; 72:1211-1218. [PMID: 15362451 DOI: 10.1007/s00128-004-0372-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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Singh KP. Electron acceleration by an intense short pulse laser in a static magnetic field in vacuum. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:056410. [PMID: 15244954 DOI: 10.1103/physreve.69.056410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2003] [Revised: 12/22/2003] [Indexed: 05/24/2023]
Abstract
Electron acceleration by a laser pulse having Gaussian radial and temporal profiles of intensity has been studied in a static magnetic field in vacuum. The starting point of the magnetic field has been taken around the point where the peak of the pulse interacts with the electron and the direction of the static magnetic field is taken to be the same as that of the magnetic field of the laser pulse. The electron gains considerable energy and retains it in the form of cyclotron oscillations even after the passing of the laser pulse in the presence of an optimum static magnetic field. The optimum value of the magnetic field decreases with laser intensity and initial electron energy. The energy gain also depends upon the laser spot size and peaks for a suitable value. The energy gained by the electron increases with laser intensity and initial electron energy. The electron trajectory and energy gain for different parameters such as laser intensity, initial electron energy, and laser spot size have been presented.
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Singh KP, Gupta DN, Tripathi VK, Gupta VL. Electron acceleration by a self-diverging intense laser pulse. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 69:046406. [PMID: 15169105 DOI: 10.1103/physreve.69.046406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2003] [Indexed: 05/24/2023]
Abstract
Electron acceleration by a laser pulse having a Gaussian radial and temporal profile of intensity has been studied. The interaction region is vacuum followed by a gas. The starting point of the gas region has been chosen around the point at which the peak of the pulse interacts with the electron. The tunnel ionization of the gas causes a defocusing of the laser pulse and the electron experiences the action of a ponderomotive deceleration at the trailing part of the pulse with a lower intensity rather than an acceleration at the rising part of the laser pulse with a high intensity, and thus gains net energy. The initial density of the neutral gas atoms should be high enough to properly defocus the pulse; otherwise the electron experiences some deceleration during the trailing part of the pulse and the net energy gain is reduced. The rate of tunnel ionization increases with the increase in the laser intensity and the initial density of neutral gas atoms, and with the decreases in the laser spot size, which causes more defocusing of the laser pulse. The required initial density of neutral gas atoms decreases with the increase in the laser intensity and also with the decrease in the laser spot size.
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Singh KP, Sanyal AK. Effect of undernutrition and subsequent rehabilitation on brain 5-HT (serotonin) profile of developing newborn rats. INDIAN JOURNAL OF MEDICAL SCIENCES 2004; 58:155-60. [PMID: 15122051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
For littermate comparison, undernutrition in half of the pups of a litter was induced by 12h maternal deprivation from day 5 to day 18 postnatal. Subsequently, undernourished suckling rats were rehabilitated. Brain 5-HT concentrations and its turnover rate were measured on different days of age up to the period of 3 months. Brain 5-HT concentration was approximately half of the adult level at birth and increased progressively, except with a steep fall on day 18 postnatal, to the adult level by day 25 postnatal and thereafter it did not vary much on different days of age. Undernourished newborn rats showed significantly low level of brain 5-HT on day 9 and significantly higher concentrations on day 12 and 18 postnatal, whereas, rehabilitated rats showed comparable brain 5-HT concentrations with that of their nourished littermates. It is concluded that undernutrition had affected the brain 5-HT concentration and its turnover rate. Brain 5-HT concentration was low during early phase and was more during late phase of undernutrition. Rehabilitation of undernourished rats restored the brain 5-HT concentration similar to that of their nourished littermates.
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Singh KP, Mohan D, Sinha S, Dalwani R. Impact assessment of treated/untreated wastewater toxicants discharged by sewage treatment plants on health, agricultural, and environmental quality in the wastewater disposal area. CHEMOSPHERE 2004; 55:227-55. [PMID: 14761695 DOI: 10.1016/j.chemosphere.2003.10.050] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2003] [Revised: 09/30/2003] [Accepted: 10/24/2003] [Indexed: 05/12/2023]
Abstract
Studies were undertaken to assess the impact of wastewater/sludge disposal (metals and pesticides) from sewage treatment plants (STPs) in Jajmau, Kanpur (5 MLD) and Dinapur, Varanasi (80 MLD), on health, agriculture and environmental quality in the receiving/application areas around Kanpur and Varanasi in Uttar Pradesh, India. The raw, treated and mixed treated urban wastewater samples were collected from the inlet and outlet points of the plants during peak (morning and evening) and non-peak (noon) hours. The impact of the treated wastewater toxicants (metals and pesticides) on the environmental quality of the disposal area was assessed in terms of their levels in different media samples viz., water, soil, crops, vegetation, and food grains. The data generated show elevated levels of metals and pesticides in all the environmental media, suggesting a definite adverse impact on the environmental quality of the disposal area. The critical levels of the heavy metals in the soil for agricultural crops are found to be much higher than those observed in the study areas receiving no effluents. The sludge from the STPs has both positive and negative impacts on agriculture as it is loaded with high levels of toxic heavy metals and pesticides, but also enriched with several useful ingredients such as N, P, and K providing fertilizer values. The sludge studied had cadmium, chromium and nickel levels above tolerable levels as prescribed for agricultural and lands application. Bio-monitoring of the metals and pesticides levels in the human blood and urine of the different population groups under study areas was undertaken. All the different approaches indicated a considerable risk and impact of heavy metals and pesticides on human health in the exposed areas receiving the wastewater from the STPs.
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Singh S, Malhotra V, Singh KP, Madhu SV, Tandon OP. Role of yoga in modifying certain cardiovascular functions in type 2 diabetic patients. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 2004; 52:203-6. [PMID: 15636309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
OBJECTIVES 1. To study the effect of forty days of Yogic exercises on cardiac functions in Type 2 Diabetics. 2. To study the effect of forty days of Yogic exercises on blood glucose level, glycosylated hemoglobin. METHODS The present study done in twenty-four Type 2 DM cases provides metabolic and clinical evidence of improvement in glycaemic control and autonomic functions. These middle-aged subjects were type II diabetics on antihyperglycaemic and dietary regimen. Their baseline fasting and postprandial blood glucose and glycosylated Hb were monitored along with autonomic function studies. The expert gave these patients training in yoga asanas and they pursued those 30-40 min/day for 40 days under guidance. These asanas consisted of 13 well known postures, done in a sequence. After 40 days of yoga asanas regimen, the parameters were repeated. RESULTS The results indicate that there was significant decrease in fasting blood glucose levels from basal 190.08 +/- 18.54 in mg/dl to 141.5 +/- 16.3 in mg/dl after yoga regimen. The post prandial blood glucose levels decreased from 276.54 +/- 20.62 in mg/dl to 201.75 +/- 21.24 in mg/dl, glycosylated hemoglobin showed a decrease from 9.03 +/- 0.29% to 7.83 +/- 0.53% after yoga regimen. The pulse rate, systolic and diastolic blood pressure decreased significantly (from 86.45 +/- 2.0 to 77.65 +/- 2.5 pulse/min, from 142.0 +/- 3.9 to 126.0 +/- 3.2 mm of Hg and from 86.7 +/- 2.5 mm of Hg to 75.5 +/- 2.1 mm of Hg after yoga regimen respectively). Corrected QT interval (QTc) decreased from 0.42 +/- 0.0 to 0.40 +/- 0.0. CONCLUSION These findings suggest that better glycaemic control and stable autonomic functions can be obtained in Type 2 DM cases with yoga asanas and pranayama. The exact mechanism as to how these postures and controlled breathing interact with somato-neuro-endocrine mechanism affecting metabolic and autonomic functions remains to be worked out.
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Sinha S, Pandey K, Mohan D, Singh KP. Removal of Fluoride from Aqueous Solutions by Eichhornia crassipes Biomass and Its Carbonized Form. Ind Eng Chem Res 2003. [DOI: 10.1021/ie030544k] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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183
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Singh KP, Angiras NN. Sensitivity of newly released varieties of rice to herbicides. JOURNAL OF ENVIRONMENTAL BIOLOGY 2003; 24:357-358. [PMID: 15259616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A field experiment was carried out during Kharif 1999 at experimental farm of CSK HPKV Palampur to check the sensitivity of newly released varieties to herbicides in direct seeded puddled rice. Experiment was conducted in randomized block design with nine treatment combinations each replicated thrice. Treatments consisted of combinations of three-weed control methods viz., two hand weeding, butachlor 2.0 kg/ha and pretilachlor 0.8 kg/ha and three rice varieties RP-2421, HPR-957 and HPR-927. It can be concluded from the study that HPR-957 was sensitive to butachlor 2.0 kg/ha and pretilachlor 0.8 kg/ha herbicides.
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Singh M, Singh KP, Shaligram P. Conjoined twins cephalopagus janiceps monosymmetros: a case report. BIRTH DEFECTS RESEARCH. PART A, CLINICAL AND MOLECULAR TERATOLOGY 2003; 67:268-72. [PMID: 12854662 DOI: 10.1002/bdra.10042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND We present an extremely rare case of Janiceps type of female cephalopagus conjoined twins. Various pathological mechanisms that may be responsible for abnormal morphological development (limited to the conjoined part and normal morphological development in free lower abdomen and pelvis) are discussed. METHODS Conjoined twins were obtained from a hospital, fixed in formalin, and dissected to observe and report the abnormalities present. RESULTS Anatomical features included development of normal face on one side, rudimentary face (two pinna only) on the opposite side, two cerebra each connected to the eye ball of its own side byoptic nerve without any chiasma formation, two brain stems, two spinal cords, normally developed vertebral columns, four upper limbs, four lower limbs, a single shared foregut and small intestine up to Meckel's diverticulum beyond which it duplicated for the two twins, patent large intestines and anal canals. The genitourinary system was developed normally in both twins. The heart of one twin was relatively hypoplastic with the lungs. The liver was herniated on one side and the other side it was hypoplastic without any herniation. Gall bladder was absent on both sides. Conjoined hepatic ducts from both livers and the only pancreatic duct drained into esophagogastric junction. CONCLUSIONS We propose that the development of upper abnormally conjoined parts and lower normally developed parts of the body of both the twins may be attributed to the factors associated with variable degrees of the conjoining, dysgenetic (developmental) defects, and deformations because of crowding in utero.
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Singh KP, Mohan D, Sinha S, Tondon GS, Gosh D. Color Removal from Wastewater Using Low-Cost Activated Carbon Derived from Agricultural Waste Material. Ind Eng Chem Res 2003. [DOI: 10.1021/ie020800d] [Citation(s) in RCA: 252] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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186
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Singh KP, Sanyal AK. Effect of undernutrition on morphine analgesia, haloperidol catalepsy and pentobarbitone sodium hypnosis in developing new born rats. INDIAN JOURNAL OF MEDICAL SCIENCES 2003; 57:164-70. [PMID: 14510349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
In the present study, half of the pups of a litter were undernourished by 12 h daily maternal deprivation from day 5 to day 18 postnatal and were subsequently nutritionally rehabilitated. Responses of CNS-acting drugs (morphine analgesia, pentobarbitone sodium hypnosis, haloperidol catalepsy) were studied at the age of day 9, 12 and 18 in maternally deprived and of day 25 in nutritionally rehabilitated new born rats as compared to that of their nourished littermates. The results showed that the response of these CNS-acting drugs was maximum at the age of day 9 postnatal and progressively decreased thereafter as the age of the animal advanced. The responses of these drugs in maternally deprived animals varied on different days of undernourishment as compared to that of their nourished littermates. The responses were significantly less in first half and were significantly more in second half period of undernourishment. The changes observed in the responses of these CNS-acting drugs were directly related to the changes observed in brain serotonin level in maternally deprived and nutritionally rehabilitated new born rats. The present findings suggest that the nature and degree of undernutrition imposed in suckling rats might only produce temporary effects on the response of CNS-actin drugs and on brain serotonin levels which is reversible if undernourished new born rats were nutritionally rehabilitated on an appropriate time of brain development.
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Singh KP, Ropars G, Brunel M, Le Floch A. Lever-assisted two-noise stochastic resonance. PHYSICAL REVIEW LETTERS 2003; 90:073901. [PMID: 12633227 DOI: 10.1103/physrevlett.90.073901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2002] [Indexed: 05/24/2023]
Abstract
A critical interplay of two correlated noises in a nonlinear symmetrical two-well potential system is experimentally demonstrated. One state can become completely noise free, leading to an infinite Kramers time. If an independent lever breaks the potential symmetry, stochastic resonance is recovered. In this new regime, we obtain a plateau, i.e., a high signal-to-noise ratio even for vanishing forcing signals.
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Sarma BK, Singh UP, Singh KP. Variability in Indian isolates of Sclerotium rolfsii. Mycologia 2002; 94:1051-1058. [PMID: 21156576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Variability among 26 isolates of Sclerotium rolfsii collected from various hosts/soil samples and localities in India is reported. The isolates varied in colony morphology, mycelial growth rate, sclerotium formation, teleomorph production and sclerotial size and color. Out of 26 isolates, only 4 produced the teleomorph stage on Cyperus rotundus rhizome meal agar medium. Mycelial incompatibility among the isolates was also seen, and out of 325 combinations, only 29 combinations (8.9%) showed compatible reactions. Based on mycelial compatibility, 13 vegetative incompatibility groups (VCG) were identified among the isolates. HPLC analysis of the ethyl acetate fraction of culture filtrates of the isolates revealed 10-22 peaks. Six peaks were identified as gallic, oxalic, ferulic, indole-3-acetic acid (IAA), chlorogenic, and cinnamic acids. Oxalic, IAA, and cinnamic acids were present in the culture filtrates of all the isolates in varying amounts. The other three phenolic acids were not detected in some of the isolates. A comparative HPLC analysis of sclerotial exudate, sclerotia, mycelia, and culture filtrates of two S. rolfsii isolates (leaf spot- and collar rot-causing) producing different symptoms on their respective hosts revealed variation in the content of phenolic acids, IAA, and oxalic acid.
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Singh KP. Intergenerational differences in fertility: a note on the inheritance of fecundity. SOCIAL ACTION 2002; 29:178-84. [PMID: 12336548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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190
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Singh KP, Sanyal AK. Standardisation of evoked response, threshold reaction time and morphine doses for analgesia in newborn nourished and undernourished suckling rats to noxious stimulus. INDIAN JOURNAL OF MEDICAL SCIENCES 2002; 56:481-5. [PMID: 12712757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
In the present study, the different criterias to assess the analgesic response of morphine in newborn suckling rats on "Eddy's hot plate" were modified. Initially, the intensity of applied heat stimulus to evoke the "cut off response" was adjusted to 50 degrees C. Different reproducible characteristic cut off responses (running and turning on back or raising fore and hind paws alternately) were selected for newborn suckling rats of varying age groups. The results revealed that newborn suckling rats are highly sensitive to morphine. The doses of morphine needed for producing a reasonable degree of analgesia on body weight basis were 0.1 mg/kg for 9 days old rats and 1.0 mg/kg for 18 days old rats. This procedure seems to be of great value in studying the analgesic effect of a drug in newborn suckling rats.
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Malhotra V, Singh S, Singh KP, Gupta P, Sharma SB, Madhu SV, Tandon OP. Study of yoga asanas in assessment of pulmonary function in NIDDM patients. INDIAN JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 2002; 46:313-20. [PMID: 12613394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Certain yoga asanas if practiced regularly are known to have beneficial effects on human body. These yoga practices might be interacting with various, somato-neuro-endocrine mechanisms to have therapeutic effects. The present study done in twenty four NIDDM patients of 30 to 60 year old, provides metabolic and clinical evidence of improvement in glycaemic control and pulmonary functions. These middle-aged subjects were type II diabetics on antihyperglycaemic and dietary regimen. Their baseline fasting and postprandial blood glucose and glycosylated Hb were monitored along with pulmonary function studies. The expert gave these patients training in yoga asanas and were pursed 30-40 min/day for 40 days under guidance. These asanas consisted of 13 well known postures, done in a sequence. After 40 days of yoga asanas regimen, the parameters were repeated. The results indicate that there was significant decrease in fasting blood glucose levels (basal 190.08 +/- 90.8 in mg/dl to 141.5 +/- 79.8 in mg/dl). The postprandial blood glucose levels also decreased (276.54 +/- 101.0 in mg/dl to 201.75 +/- 104.1 in mg/dl), glycosylated hemoglobin showed a decrease (9.03 +/- 1.4% to 7.83 +/- 2.6%). The FEV1, FVC, PEFR, MVV increased significantly (1.81 +/- 0.4 lt to 2.08 +/- 0.4 lt, 2.20 +/- 0.6 lt to 2.37 +/- 0.5 lt, 3.30 +/- 1.0 lt/s to 4.43 +/- 1.4 lt/s and 64.59 +/- 25.7 lt min to 76.28 +/- 28.1 lt/min respectively). FEV1/FVC% improved (85 +/- 0.2% to 89 +/- 0.1%). These findings suggest that better glycaemic control and pulmonary functions can be obtained in NIDDM cases with yoga asanas and pranayama. The exact mechanism as to how these postures and controlled breathing, interact with somato-neuro-endocrine mechanism affecting metabolic and pulmonary functions remains to be worked out.
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Mohan D, Singh KP, Singh G, Kumar K. Removal of Dyes from Wastewater Using Flyash, a Low-Cost Adsorbent†. Ind Eng Chem Res 2002. [DOI: 10.1021/ie010667+] [Citation(s) in RCA: 262] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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193
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Singh KP, Singh M. Effect of prenatal haloperidol exposure on behavioral alterations in rats. Neurotoxicol Teratol 2002; 24:497-502. [PMID: 12127895 DOI: 10.1016/s0892-0362(02)00189-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pregnant Charles-Foster rats were exposed to haloperidol (HAL), a neuroleptic drug that binds to and blocks dopamine (DA) receptor subtypes at a dose of 2.5 mg/kg body weight (intraperitoneally) from Gestation Day (GD) 12 to 20. The animals from both treated as well as vehicle control groups were allowed to deliver on GD 21. The offspring culled at birth on the basis of sex and weight were subjected to behavioral tests at the age of 8 weeks. The HAL-treated rat offspring showed a significant increase in anxiogenic behavior on the open field, elevated plus-maze and elevated zero-maze tests when compared with the vehicle-treated (control) rat offspring of the same age group. These findings suggest that prenatal exposure to HAL during a critical period of brain development leaves a lasting imprint on the brain, resulting in abnormal anxiety states, possibly through dopaminergic neurotransmission mechanisms.
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Mohan D, Singh KP. Single- and multi-component adsorption of cadmium and zinc using activated carbon derived from bagasse--an agricultural waste. WATER RESEARCH 2002; 36:2304-18. [PMID: 12108723 DOI: 10.1016/s0043-1354(01)00447-x] [Citation(s) in RCA: 436] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The use of low-cost activated carbon derived from bagasse, an agricultural waste material, has been investigated as a replacement for the current expensive methods of removing heavy metals from wastewater. With a view to find a suitable application of the material, activated carbon has been derived, characterized and utilized for the removal of cadmium and zinc. The uptake of cadmium was found to be slightly greater than that of zinc and the sorption capacity increases with increase in temperature. The adsorption studies were carried out both in single- and multi-component systems. Adsorption data on derived carbon follows both the Freundlich and Langmuir models. The data are better fitted by the Freundlich isotherm as compared to Langmuir in both the single- and multi-component systems. Isotherms have been used to obtain the thermodynamic parameters. The kinetics of adsorption depends on the adsorbate concentration and the physical and chemical characteristics of the adsorbent. Studies were conducted to delineate the effect of temperature, initial adsorbate concentration, particle size of the adsorbent and solid-to-liquid ratio. On the basis of these studies, various parameters such as mass transfer coefficient, effective diffusion coefficient, activation energy and entropy of activation were evaluated to establish the mechanisms. It was concluded that the adsorption occurs through a film diffusion mechanism at low as well as at higher concentrations.
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Singh KP, Mohan D, Tandon GS, Gupta GSD. Vapor-Phase Adsorption of Hexane and Benzene on Activated Carbon Fabric Cloth: Equilibria and Rate Studies. Ind Eng Chem Res 2002. [DOI: 10.1021/ie0105674] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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196
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McCabe MJ, Singh KP, Reiners JJ. Low level lead exposure in vitro stimulates the proliferation and expansion of alloantigen-reactive CD4(high) T cells. Toxicol Appl Pharmacol 2001; 177:219-31. [PMID: 11749121 DOI: 10.1006/taap.2001.9307] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
T cells are believed to be critical functional targets of Pb immunotoxicity. In this study, low concentrations of lead (i.e., as low as 0.1 microM approximately 2 microg/dl) were found to markedly enhance the allogeneic mixed lymphocyte reaction-an assay of CD4(+) T cell responsiveness. Cell cycle analysis of cells recovered from allogeneic mixed lymphocyte cultures revealed that Pb stimulated a substantial increase in the proportion of cycling alloreactive CD4(+) T cells. The enhanced alloproliferative response was characterized by an increased population of lymphoblasts expressing heightened cell surface expression of CD4 (i.e., CD4(high) cells). Successive rounds of cell division were monitored using the cell division dye 5- (and 6)-carboxyfluorecein diacetate succinimyl ester and it was determined that the CD4(high) subpopulation comprised the expanding alloreactive T cells, which ultimately took on the phenotype of memory/effector T cells (i.e., CD44(high), CD45RB(low), CD69(high), and CD162(high)). Enhancement of T cell proliferation by lead was selective for responsiveness to alloantigen, as lead had no effect on T cell proliferation induced by mitogens or superantigen, processes that unlike alloreactivity are not dependent on antigen presentation. Collectively, these data suggest that Pb enhances alloantigen-specific T cell proliferation through an indirect mechanism involving altered antigen processing/presentation, resulting in marked clonal expansion or repertoire expansion of alloreactive T cell clones. Consistent with this suggestion was the finding that a single exposure to Pb during alloantigen priming elicited a population of CD4(+) T cells that was hyperresponsive to further alloantigen stimulation and neither lead dependent nor lead responsive.
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Singh KP, Ropars G, Brunel M, Bretenaker F, Le Floch A. Stochastic resonances in an optical two-order parameter vectorial system. PHYSICAL REVIEW LETTERS 2001; 87:213901. [PMID: 11736339 DOI: 10.1103/physrevlett.87.213901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2001] [Indexed: 05/23/2023]
Abstract
We show experimentally that optical two-dimensional systems such as vectorial lasers can exhibit novel stochastic resonances. All optical noise and modulation of this system allows the isolation of so-called inhibitional and rotational stochastic resonances. In particular, incoherent rotational tunneling is shown to be sensitive enough to be also induced by Faraday noise and by quantum noise, i.e., external spontaneous emission.
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Raina SN, Rani V, Kojima T, Ogihara Y, Singh KP, Devarumath RM. RAPD and ISSR fingerprints as useful genetic markers for analysis of genetic diversity, varietal identification, and phylogenetic relationships in peanut (Arachis hypogaea) cultivars and wild species. Genome 2001. [DOI: 10.1139/g01-064] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Twenty-one random and 29 SSR primers were used to assess genetic variation and interrelationships among subspecies and botanical varieties of cultivated peanut, Arachis hypogaea (2n = 4x = 40), and phylogenetic relationships among cultivated peanut and wild species of the genus Arachis. In contrast with the previous generalization that peanut accessions lack genetic variation, both random and SSR primers revealed 42.7 and 54.4% polymorphism, respectively, among 220 and 124 genetic loci amplified from 13 accessions. Moreover, the dendrograms based on RAPD, ISSR, and RAPD + ISSR data precisely organized the five botanical varieties of the two subspecies into five clusters. One SSR primer was identified that could distinguish all the accessions analysed within a variety. Although the polymorphic index content varied from 0.1 to 0.5 for both ISSR and RAPD markers, primer index values were substantially higher for RAPD primers (0.354.65) than for SSR primers (0.351.73). It was possible to identify accessions, particularly those of divergent origins, by RAPD and (or) ISSR fingerprints. Based on these results, marker-based genetic improvement in A. hypogaea appears possible. None of the 486 RAPD and 330 ISSR amplification products were found to be commonly shared among 13 species of section Arachis and one species each of sections Heteranthae, Rhizomatosae, and Procumbentes. Dendrograms constructed from RAPD, ISSR, and RAPD + ISSR data showed overall similar topologies. They could be resolved into four groups corresponding to the species grouped in four taxonomic sections. The present results strongly support the view that Arachis monticola (2n = 4x = 40) and A. hypogaea are very closely related, and indicate that A. villosa and A. ipaensis are the diploid wild progenitors of these tetraploid species.Key words: Arachis hypogaea, genetic markers, varietal identification, DNA polymorphism, Arachis species.
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Raina SN, Rani V, Kojima T, Ogihara Y, Singh KP, Devarumath RM. RAPD and ISSR fingerprints as useful genetic markers for analysis of genetic diversity, varietal identification, and phylogenetic relationships in peanut (Arachis hypogaea) cultivars and wild species. Genome 2001; 44:763-72. [PMID: 11681599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Abstract: Twenty-one random and 29 SSR primers were used to assess genetic variation and interrelationships among subspecies and botanical varieties of cultivated peanut, Arachis hypogaea (2n = 4x = 40), and phylogenetic relationships among cultivated peanut and wild species of the genus Arachis. In contrast with the previous generalization that peanut accessions lack genetic variation, both random and SSR primers revealed 42.7 and 54.4% polymorphism, respectively, among 220 and 124 genetic loci amplified from 13 accessions. Moreover, the dendrograms based on RAPD, ISSR, and RAPD + ISSR data precisely organized the five botanical varieties of the two subspecies into five clusters. One SSR primer was identified that could distinguish all the accessions analysed within a variety. Although the polymorphic index content varied from 0.1 to 0.5 for both ISSR and RAPD markers, primer index values were substantially higher for RAPD primers (0.35-4.65) than for SSR primers (0.35-1.73). It was possible to identify accessions, particularly those of divergent origins, by RAPD and (or) ISSR fingerprints. Based on these results, marker-based genetic improvement in A. hypogaea appears possible. None of the 486 RAPD and 330 ISSR amplification products were found to be commonly shared among 13 species of section Arachis and one species each of sections Heteranthae, Rhizomatosae, and Procumbentes. Dendrograms constructed from RAPD, ISSR, and RAPD + ISSR data showed overall similar topologies. They could be resolved into four groups corresponding to the species grouped in four taxonomic sections. The present results strongly support the view that Arachis monticola (2n = 4x = 40) and A. hypogaea are very closely related, and indicate that A. villosa and A. ipaensis are the diploid wild progenitors of these tetraploid species.
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Singh KP, Roy D. Identification of novel breast tumor-specific mutation(s) in the q11.2 region of chromosome 17 by RAPD/AP-PCR fingerprinting. Gene 2001; 269:33-43. [PMID: 11376935 DOI: 10.1016/s0378-1119(01)00458-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Analysis of genetic instability in breast cancer tissues compared to uninvolved breast tissues from the same individuals by RAPD (random amplified polymorphic DNA)/AP-PCR (arbitrarily primed PCR) fingerprinting using 30 arbitrary primers revealed 190 amplified DNA fragments. Presumably, each of these represents a gene locus in a different region of the genome of breast cancer tissues. Among these amplified DNA fragments, 65 (34.2%) exhibited presence and absence or reductions and enhancements in the intensity in breast cancer tissues compared to uninvolved breast tissues from the same individuals, and 11 amplified DNA fragments (5.7%) represented polymorphisms in the uninvolved human breast tissues. Reductions and enhancements in the intensity of some of the amplified fragments were observed indicating allelic gains or losses in the breast tumor genome compared to the matched uninvolved tissue genome. The presence or absence of some of the amplified DNA fragments were observed in this study indicating homozygous deletions or insertions in the breast tumor DNA compared to the matched uninvolved tissue DNA. Notably, an insertion of a 1270 bp amplified fragment was observed in 81% (17 of 21) of the tumor samples using the primer, OPC04. This amplified fragment resolved into two, 1200 and 1300 bp, single-stranded amplified fragments on the denaturing sequencing gel. This separation into single-stranded fragments suggests that the amplified fragment contains a conformation that is semistable. The 1270 bp amplified fragment localizes to the q11.2 region of chromosome 17. Sequence analysis of this fragment showed a significant DNA base sequence similarity (93%) with one of the breast tumor-specific human EST. The similarity with EST sequences and RT-PCR analysis showed that a part of this amplified fragment is from the coding region of the genome. Any one of the events observed in this study could play an important role in the development of breast cancer or could occur during the clonal expansion of the genetically unstable breast cells.
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